Nonwovens, films, textiles, papers and paperboard materials as normally manufactured are relatively smooth, flat-surfaced and uniform in density, and are thin compared to their length and width. When thicker structures with at least one smooth side are desired, well-known corrugation and lamination processes are commonly used to combine and bond at least one relatively flat roll good material with at least one other relatively flat roll good material which is corrugated into a sinuous or undulant form and bonded to the relatively flat material, usually with some kind of bonding agent.
The resulting lamination yields a combined bonded laminate structure which is relatively thicker and therefore lower in overall density than it would be had the roll goods been combined and bonded together in their original flat forms without corrugation. In addition, laminations combining one or more corrugated elements—bonded to one or more flat supporting elements—often offer additional beneficial properties to the resulting laminated structure, such as controllable z-direction compressibility, overall structural rigidity, load bearing capability, cushioning abilities, insulation properties and a wide variety of other structural and functional benefits with reasonably efficient use of raw materials.
The common corrugated paperboard box that is widely used to protect products during shipment and storage is one illustrative example of the established lamination and corrugation processes in common use. The bonded combination of at least one relatively flat-surface with at least one corrugated, sinuous or undulant layer results in a lower overall density in the combined structure with such desirable functional properties as stiffness control, structural rigidity, and load bearing strength, and with a desirable smooth outer surface for printability and appearance. While lamination techniques are useful, they require separately-made roll goods, corrugation and lamination process equipment to produce raised corrugated elements bonded to other flat roll good elements.